THERIO L4-5 Bovine Placentation Pregnancy Parturition

drhartz's version from 2017-09-14 18:26


Question Answer
what are the 4 definitive signs of pregnancy by palpation per rectum?1. Fetus
2. amniotic vesicle
3. chorioallantoic (fetal) membrane slip "FMS"
4. placentomes
when are amniotic vesicles felt?30-65 days
when is the chorioallantoic fetal membrane slip felt?35-90 days
when are the placentomes felt?70 days easiest after 120 days
size of fetus at 60 days?mouse
size of fetus at 90 days?rat
size of fetus at 120 days?small cat
size of fetus at 150 days?large cat
size of fetus at 180 days?beagle dog
mouse size at what day?60
rat size at what day?90
small cat size at what day?120
large cat size at what day?150
beagle dog size at what day?180
why do we want to know the size of fetuses at specific days of gestation?evaluations of abortion. size of the fetus can tell us at what stage of pregnancy the abortion took place
what are the 3 palpable uterine changes that are signs of pregnancy?1. Thinning of the Uterine Wall
2. increase in Diameter of the Uterine Horns
3. presence of Fluid - Turgidity (swollen)
how thick is the non pregnant uterus compared to a pregnant one? - Not preg uterus: 9-10mm
- preg uterus: intercaruncular areas are 2mm
WHEN can you feel fluid within the uterus (turgid)? what does it feel LIKE? fluid detectable day 35-40
feels like a water balloon
between days 30-50 what 2 things can an experienced vet feel for definitive dx of pregnancy?1. presence of fluid in uterus 2. thin walled uterine horn
between days 30-90 what 2 thing can be palpated for definitive dx of pregnancy?1. amnionic vesicle
2. chorioallantoic fetal membrane slip
AFTER 90 days what two things can be felt to dx pregnancy?1. fetus 3-4 months routine
2. placentomes day 70 but easier at 120
3. fremitus pulse of uterine artery
what is the amnionic vesicle ?a small balloon with the larger balloon of the allantoic sac
WHEN is pressure from the amnion > allantois during early pregnancy day 30-65
HOW is the amnion felt?free portion of the horn - gently palpate the uterine horn until a round, firm, intrauterine structure is felt
WHEN is the amnion NO longer felt? & WHY?beyond 65 days bc elongation and fluid accumulation of the allantois??? makes the amnion less definitive
Between days 35-90
1. HOW should you feel for the chorioallantoic membrane "FMS"
2. What will this help you find?
3. Where must you feel to avoid complications?
1. whole horn diameter should be pinched
2. connective tissue & BV banding from uterine floor
3. at the OVARIAN end of the uterine horn to avoid crushig the conceptus
Clinicians should NOT look for the chorioallantoic FMS unless they identify what first?fluid in the uterus
why should fluid in the uterus be identified before looking for the FML?one can pinch the uterine horn hard enough that the endometrium will slip within ones fingers just from crushing the uterine wall
when are placentomes more accessible than the fetus on palpation?from 5-7 months of pregnancy
what will the placentomes feel like?a bag filled with water and cherries
how do the placentomes differ between the two uterine horns?the placentomes of the pregnant horn are larger
where should you feel for placentomes during the earlier part of pregnancy?best felt in the midline & at the level of the horn near the intercornual ligament by palpating the dorsal wall of the uterus
which ligament is a marker for feeling placentomes?intercornual ligament
what are 2 exam findings in addition to the 4 definitive signs?1. inc diameter of Uterine Artery (esp on the pregnant side) 2. Fremitus Pulse of the Uterine Artery

Palpation of Uterine Artery

Question Answer
where can the uterine artery be found?in the broad ligament passing forward from the iliac shaft --> the pelvic brim --> mid cornual region
where can the fremitus pulse of the uterine artery be felt?where the artery leaves the pelvis and enters the abdomen
which artery is more mobile and which is adhered to the iliac shaft? why does this matter?uterine artery is more mobile than the iliac. the uterine artery will move away from the ilium in late pregnancy. important in distinguishing feel: cannot get fingers around iliac
WHEN will you feel that the uterine artery is enlarged?at 80-90 days and progresses to fremitus (90-120 days)
WHEN will you feel a fremitus pulse in the uterine artery?90-120 days later progresses to --> "GUSHING"
what pathology will cause an enlargement of the uterine artery? what time period (in days) of pregnancy will this resemble?Pyometra 90-120 day pregnancy
diameter of uterine artery (pregnant side) @ 90 days?3 mm
diameter of uterine artery (pregnant side) @ 120 days?6 mm
diameter of uterine artery (pregnant side) @ 150 days?9 mm
diameter of uterine artery (pregnant side) @ 180 days?12 mm
12 mm uterine artery is present @ what day of pregnancy?180 days
9 mm uterine artery is present @ what day of pregnancy?150 days
6 mm uterine artery is present @ what day of pregnancy?120 days
3 mm uterine artery is present @ what day of pregnancy?90 days

Palpation of Fetus

Question Answer
Palpation of fetus is routine at how many months?
difficult at how many months? WHY
Accessible again?
routine: 3-4 months
difficult: 5-6 months due to depth of abdomen
accessible again at 7-9 months
when can you elicit fetal movement?AFTER 6 months
when will the amniotic vesicle hinder palpation of the fetus?before 60-70 days aka 2 months *do not squeeze the amniotic vesicle to try and feel!*
what should you NOT try to squeeze to palpate the fetus directly? *dangerous*amnionic vesicle
when are the ovaries not easily felt on the pregnant side? on the non pregnant side?ovary not felt on pregnant side after 4 months .. ovary not easily felt on nonpreg side after 7 months

Estimation of the Stage of Pregnancy

Question Answer
30-40 days - what 3 things are present?1. amniotic vesicle 0.7cm in diameter (half a finger wide)
2. fetal membrane slip
3. assymetry of horns
42 days - what 6 things are present?1. fluid
2. thinning of uterine wall
3. amniotic vesicle
4. fetal membranes
5. skinny ballon shape
6. inc in diametere of the uterine horn to approx 4-5 cm
65-70 days - what 2 things are significant1. amniotic vesicle disappears!!! due to loss of distinctive fluid pressure
2. uterine diameter continues to increase
12 weeks / 70 + days/ 3 months...
1. what significant feature can be felt?
2. what does it feel like?
3. how many cm in diameter?
1. the caruncles (placentomes)
2. thickenings of the uterine wall
3. 1-2 cm in diameter
palpation of fetus routine from now to 4 months rat size
16 weeks/ 110 days/ 4 months...what happens to the uterus, uterine artery, placentomes, fetal size- marked increase in the full-water-balloon feeling of the uterus
- uterine artery increased in size to a 0.5 cm & is fremitus
- placentomes the size of a nickel
- fetus size of small cat
5 months/ 150 days .. what happens to the uterus? placentomes? where is the Uterus? fetal size? can you feel it?- uterus loses turgidity - completely flaccid
- 4-5 cm (quarter size)
- Uterus is in abdomen
- fetus size of large cat.. CANT feel
6 months/ 180 days .. placentomes? fetus?placentomes half dollar size fetus size of beagle dog
7 months .. what happens to fremitus uterine artery? whats significant about fetus palpation?fetus more accessible to palpate (at 7-8 months...5-6 difficult due to depth of abdomen)
fremitus pulse becomes progressively unclear
8 months.. significant about fetus?1. risen from abdomen floor enough to easily palpate 2. can feel limbs and head of fetus

Amniotic Vesicle

Question Answer
size of amniotic vesicle @ 30-40 days?0.7 cm (half a finger)
size of amniotic vesicle @ 42 days?1.5 cm (1 finger)
size of amniotic vesicle @ 52 days?5.5 cm (3 fingers)
size of amniotic vesicle @ 58 days?7.5 cm (4 fingers)
size of amniotic vesicle @ 65 days?10.5 cm (width of hand + thumb)
0.7 cm amniotic vesicle @ what days?30-40 days
1.5 cm amniotic vesicle @ whats days?42 days
the diameter of the uterine horn increases ____ cm for each ____ days of gestation?diameter inc 10 cm every 10 days of gestation
3.8 cm amniotic vesicle @ whats days?48 days
5.5 cm amniotic vesicle @ whats days?52 days
7.5 cm amniotic vesicle @ whats days?58 days
10.5 cm amniotic vesicle @ whats days?65 days

Fetal Length

Question Answer
fetal length at 70 days1 finger
fetal length at 80 days2 fingers
fetal length at 90 days5.5 cm (3 fingers) rat size
fetal length at 100 days7.5 cm (4 fingers)
fetal length at 110 days9 cm (hand width)
fetal length at 120 days10.5 cm (hand + thumb) small cat


Question Answer
the placenta is of what origin?fetal membranes fetal origin - tissues that are formed from the development of the fertilized egg (NOT FROM THE MATERNAL SIDE) include BOTH the fetus & MEMBRANES
3 major types of placenta in domestic animals & what animals for each?1. diffuse placenta - horse & pig
2. cotyledonary placenta/placentomes - ruminants --> cotyledon fetal component / caruncles maternal
3. Zonary placenta - carnivores
what are the 3 placental membranes & 2 balloons?placental membranes: chorion, amnion, allantois
balloons: allantoic fluid & amnionic fluid
what is the chorion? what does it surround?outermost embryonic membrane - surrounding the allantoic cavity, amnion, amnionic cavity & fetus - attached to the endometrium
what is the amnion?the inner embryonic membrane that surrounds the amniotic cavity and fetus
what is the allantois? what does it surround and form? what is its function? - allantois is an extra-embryonic membrane that evaginates from the hindgut
- lines the inside of the chorion forming 1 physical membrane = chorio-allantois membrane - also lines the outside of the amnion creating forming 1 physical membrane = amnio-allantios membrane
3. provides vasculature to chorion and amnion
what is the chorioallantois ?fused chorion and allantois --> 1 physical membrane
what is the outer balloon of the placenta? what is the inner balloon of the placenta?outer balloon: allantoic fluid (membrane surrounding it - allantois)
inner balloon: amnionic fluid (membrane surrounding the fluid is the amnion)
what is the embryonic chorion attached to on the maternal side? function?attached to the endometrium for maternal/fetal transfer of essential nutrients
characteristics of the chorionic surface?rough, red/discolored aspect of the detached placenta at foaling "red bag"
role of placental membranes in providing progesterone necessary to maintain pregnancy????
characteristics of premature placental detachment at foaling in horse????
caruncle?maternal component of placenta - growths develop at specific sites in cow endometrium - found in nonpregnant cows
what attaches to the caruncle?fetal chorio-allantois forming the placentomes
caruncles are found in both uterine horns how are they utilized?fetus s associated with one horn but the fetal membranes fill both horns and utilize the caruncles in BOTH horns
2 ways the placenta prevent luteolysis (ridding of the CL) ?1. placenta prevents PGF2a luteolysis by releasing IFN tau 2. recognition of pregnancy by contact with the endometrium (elongation to fill horns)
anomalies in placental development with genetic aspects of cattle & IVF/cloning~?? hdyrops ??
cows major placental dz? emergency?retained placenta, No

Termination of pregnancy

Question Answer
indication for elective termination of pregnancy?1. mismatching - wrong bull, heifer too young, heifer going to feedlot
2. pathological pregnancy - hydroallantois, hydramnios, mummification, maceration
pregnancy is maintained by progesterone, what produces it? (2)CL & Placenta
when does CL provide progesterone for pregnancy?0-150 days then 250 - Term (270/295) (last month of gestation)
when does placenta provide progesterone for pregnancy?after 150 days placenta produces progesterone
when will ovariectomy cause abortion?before 5 months
when can an ovariectomy be performed without terminating pregnancy?after 200 days pregnancy will continue
what are some complications to performing an ovariectomy after 200 days? (4)- P4 decreases to lower levels
- gestations is shortened by 2 weeks
- dystocia
- retained placenta
throughout pregnancy progesterone fluctuates between ______ ng/ml6-15 ng/ml
0-150 days gestation what provides P4?CL
150 - 250 days gestation what provides P4?Placenta
250 - 270/295 days gestation what provides P4?CL
Abortion/Parturition is induced by decreasing ____ to ____ ng/ ml-progesterone
- less than or equal to 1 ng/ml
physical methods of terminating pregnancy? (not most common)rupture of AV, decapitation of fetus between 65-90 days, IU infusions, enucleation of CL
MOST COMMON methods of terminating pregnancy? (3)PGF2a, PGF2a ananlogs, glucocorticoids

Pharmacologic Agents for pregnancy termination

Question Answer
pharm agents for terminating pregnancy (4 )1. PGF2a
2. Corticosterioids
3. Estrogen
4. Oxytocin
when is CL sensitive to PGF2a?5-7 days after ovulation
PGF2a causing abortion from 5 days after ovulation to ____?day 150
when does PGF2a induce parturition?final month of pregnancy --> day 250
when do glucocorticoids/corticosteroids induce abortion? what must they be combined with?during 150-250 days combined with prostaglandin
when do glucocorticoids/corticosteroids induce parturition?final month of pregnancy --> day 250
estrogen causes luteolysis & abortion when?0-150 days
estrogen can aid speed of induction of parturition with combined with what?glucocorticoids
oxytocin interferes with CL formation when?2-7 days after estrus